Bicycle



(No Model.) 2 Sheets-Sheet 1.

A L. ADAMS.

BICYCLE.

No. 579,732. Patented Mar. 30, 1897 [P am: 9

Q; MI 3 (No Model.) v 2 Sheets-Sheet 2.

A. L. ADAMS. BIGYGLE.

No. 579,732. Patented Mar. 30, 1897.

WITNESSES: v

Wit I NITED STATES ATENT Prion.

ABRAHAM L. ADAMS, OF BRIDGEPORT, CONNECTICUT.

BICYCLE.

SPECIFICATION forming part of Letters Patent No. 579,? 32, dated March 30, 1897.

Application filed September 19, 1895. Serial No. 562,970. (No model.)

To all whom it may concern.-

Be it known that I, ABRAHAM L. ADAMs, a citizen of the United States, residing at Bridgeport, in the county of Fairfield and State of Connecticut, have invented certain new and useful Improvements in Bicycles;

and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

My invent-ion relates to certain improvements in bicycles, but more particularly has reference to crank propulsion, the object being to so attach the pedal to the propellingcrank that the rider may at will effect the automatic lengthening or shortening of the crank leverage.

In the accompanying drawings, which form a part of this application, Figures 1 and 2 are sectional elevations showing a bicycle-crank equipped with my improvement, the position of the parts in Fig. 1 being such as to increase the leverage of the crank, while the position of the corresponding parts in Fig. 2 is such as to decrease such leverage; Fig. 3, a section at the line 0c 02 of Fig. 1; Fig. 4, a section at the line y y of Fig. 1; Fig. 5, a detail perspective of the auxiliary crank; Fig. 6, a detail perspective of the crank-pin.

Similar numbers of reference denote like parts in the several figures of the drawings.

The broad principle which underlies my invention resides in the idea of an auxiliary crank which is carried by the crank-pin of the usual bicycle-crank, while the pedal is carried by the auxiliary crank and is so journaled in connection therewith that its axis of revolution is eccentric to the axis of the crankpin. In all instances the auxiliary crank must be swung around in order to bring the pedal into a higher or lower normal horizontal plane, whereby the leverage of the bicyclecrank is shortened or lengthened.

It will be clear that the adjustments of the auxiliary crank and the locking of the same may be efiected intwo ways, as follows: First, the crank-pin may be stationary and the auxiliary crank mounted thereon after the manner of a sleeve, so as to be capable of an independent revolution, in which case a lockingdevice would be carried by the auxiliary crank and would engage with the crank-pin, or, vice versa, such device would be carried by the crank-pin and would engage with the auxiliary crank; second, the auxiliary crank might be made circular and journaled within suitable bearings in the bicycle-crank, while the crank-pin would be rigidly secured to the auxiliary crank eccentric thereof, and the pedal would be j ournaled on said pin, in which case a locking device carried by such auxiliary crank or pin would engage with the bicycle-crank, or, vice versa, said locking device carried by the bicycle-crank would engage with said auxiliary crank or pin, to effect the locking of such auxiliary crank in its adjustments. The first of these two construc tions is included in the present application, while the second construction I have made the subject-matter of a separate application for patent, filed of even date herewith and bearing Serial No. 562,971.

In order that those skilled in the art to which my invention appertains may more fully understand the same, I will now describe it in detail, and will refer to the accompanying drawings, which I have above described.

Referring to the accompanying drawings, 1 is the usual bicycle-crank, 2 the crank-pin, secured thereto in the usual manner by nut 3, and 4 is an auxiliary crank having a hub 5, which latter fits loosely around the crankpin, so as to be capable of rotation. This hub is kept in position by means of a washer 6 and nut 7, the latter engaging the inner end of the crank pin and being forced firmly against the washer.

8 is the crank-spindle for the pedal, secured to the crank 4: by means of nut 9, and around this spindle is journaled the pedal 10 in the usual manner.

Pivoted between ears 11,projecting from the hub 5, is a latch 12, and 13 is a spring which is made of wire and is of a circular shape and embraces the hub 5, one extremity of this spring being connected with the inner end of said latch.

14 are notches in the crank-pin 2, and the function of the spring 13 is to cause the latch 12 to normally engage with one of these notches, whereby the auxiliary crank and the crankpin 2 will be locked together.

15 is a lever pivoted at 16 to the auxiliary crank and resting upon the tail or outer end of the latch 12, whereby when said lever is depressed the nose or inner end of said latch will be raised out of engagement with the pin 2, thus permitting the auxiliary crank to have an independent rotation around said pin, for the purpose which I will now explain. This lever is within convenient reach of the foot of the rider, so that if the latter has been riding with the short crank leverage, as shown at Fig. 2, and desires a greater propelling leverage he merely slides his foot along the pedal, and, when the latch is brought within reach by the revolution of the crank 1, simply depresses the lever 15 with his foot and immediately releases said lever. The moment the lever is depressed the auxiliary crank commences to turn around the pin 2, and when the latch comes opposite to the notch diametrically opposed to that with which it had previous engagement said latch will be forced into said notch by the spring 13, thereby again locking the auxiliary crank and the pin rigidly together and effecting a lower normal adj ustment of the pedal, whereby the propelling leverage is increased. It will thus be seen that the crank-propelling leverage may be lengthened or shortened automatically and at the will of the rider and without any necessity on the part of the latter for dismountiug or for using any tools.

Bylen gthenin g the crank great power is obtained, and this is advantageous for the purpose of climbing bills or when it becomes necessary to ride against head'winds or upon bad roads. By shortening the leverage a rider obtains a steadier, quicker, and easier motion for traveling on a level road, and experiences less fatigue, since it is entirely unnecessary, in traveling on an ordinary good road, that a large sweep and the consequent increased action of the limbs of the rider should be had.

By alternately changing the leverage of the crank the rider is rested, and, moreover, this leverage can instantly be adapted for easy or hard travel,as the case may be.

Of course it will be obvious that the notches in the crank-pin may be placed around the same on the quarters, thus giving adjustments for three positions of the pedal, namely, two at the extreme limits of the long or short levcrage and a third between these limits, and I therefore do not wish to be confined to the two adjustments shown.

Having thus described my invention, what I claim as new, and desire to secure by Letters Patent, is

In a bicycle, the combination of the crank and the crank-pin, the auxiliary crank carried by said pin and capable of being swung around its axis, the pedal-spindle secured to said auxiliary crank eccentric to the axis of said pin, the pedal suitably journaled around said spindle, the notches in the circumference of said pin, the latch pivoted to said auxiliary crank and capable of engaging with said notches, the spring whereby said latch is normally engaged with said notches, and the lever resting upon said latch and carried by the auxiliary crank, substantially as set forth.

In testimony whereof I aflix my signature in presence of two witnesses.

ABRAHAM L. ADAMS.

Vitnesses:

F. XV. SMITH, J12, M. T. LoNcDnN. 

